Constant voltage device



Patented Mar. 6, 1934 UNITED PATENT OFFICE CONSTANT VOLTAGE DEVICE tion of Germany No Drawing. Application August 14, 1931, Serial No. 557,195. In Germany August 20, 1930 1 Claim.

Glow-discharge or gaseous-conduction lamps or tubes which operate only on a normal cathode fall as is well known involve the property that the potential drop between the electrodes thereof preserves a constant value until the surface of the cathode is covered fully with a glow-(light). The

density of the current remains constant until the cathode has become completely covered with the luminescent layer of glow. It is only after this state has been attained that the current density of the discharge and simultaneously the electrode potential will arise.

It is also known that this property may be utilized for remedying the potential fluctuations occurring in all lines or line networks, for instance, so that by the use of glow-discharge lamps in broadcast receivers of the electrical type (supplied from a supply-line) the provision of expensive condensers is avoided. By the mounting of distinct electrodes inside the gaseous-conduction lamp it is also feasible to derive differently high constant potentials.

Research, however, has shown that the glowdischarge lamps heretofore used are incapable of maintaining potential at a constant value to such a perfect degree as is required in practice. To be sure, the low frequencies will be filtered out inside the glow-discharge lamp; but the higher harmonics of a few hundred cycles which exist in all lighting circuits will not be retained by the lamp.

The present invention discloses ways and means adapted to obviate the drawback found in earlier designs. The real trouble underlying the above defect or deficiency resides in the inertia of the gases heretofore employed for constituting the carriers of the glow-discharge (neon, helium and the commercial mixtures thereof). The inertia of these gases is predicated upon their property 69 to result in metastable states of increased life or duration or to recombine with considerably greater sluggishness than typical for other gases with incidental light emission. But if the lamp is filled with a kind of gas which is free from the said inertia properties it is found that also potential fluctuations of higher frequencies may be changed by the glow-discharge lamp into current variations while the electric pd. is stabilized. Such inertialess gases are, for instance, rare gases such as argon, krypton and Xenon or any suitable mixture of these gases. Also hydrogen or nitrogen is able to follow oscillations up to 100,000 Hertz (cycles) in a way free from sluggishness so that with the use of these gases the d. c. poten- 7 tial across the terminals of the set may be readily maintained at a constant value.

I claim:

A tube for use in circuit arrangements utilized to smooth out pulsating direct current resulting, for instance, from rectifying alternating current, comprising an envelope having mounted therein at least two electrodes, and filled With a mixture of only the substantially inertialess gases, argon, krypton, xenon, hydrogen and nitrogen whereby substantially all perceptible harmonics of the fun- FRITZ MICHELSSEN. 0 

